987s Electrical Problem - i'm totally lost

[Dan Norton]

Hello All,

 

The last couple of weeks, i've had some really frustrating electrical gremlins hit my Gen 1 987s.

 

Its got a new battery as of 7 weeks ago, and a new alternator 2 years ago.

 

Its been doing the weirdest things such as;

- Infotainment screen flickering on and off.

- Dash flickering on and off.

- Window dropping and not going back up when close door.

- Rear spoiler goes up by itself.

- PSM and PASM coming on and off at will

 

however, the worst bit was a week ago when the PSM came on, it wouldn't go off, so i pulled over to switch the car off and....that was that, total black out! Just like when the battery is dead.

Even the key was stuck and wouldn't come out (as like when the battery is dead).

 

So when the recovery guy came, in order to get to the battery and open the boot lid, i showed him how to with the "live" toggle in the fuse box, and negative attached to the striker......and again, absolutely nothing! Tried with a jumper pack and leads, but it was dead, complete black out.

 

Got recovered back home (window was halfway down aswell), left it overnight in its recovered state, and the next day i went to get some tarpaulin to put over the roof and protect the inside from the impending rain  the next day.

 

When i get to the car and open the door, weirdly the door window dropped (As it does when you open the car), and the dash was on! Fully lit up.

 

I took the key out, and the dash lights stayed on! And is still on a week later.

 

The problem is i dare not start it up incase it doesn't switch itself off.

 

Has anyone experienced this before or could hint to what it might be?

Also, does anyone know a good mobile auto electrician in Lincoln / Lincolnshire.

 

Thanks in advance,

Dan

 

 

[extanker]

bad ignition switches have been know to do unusual things ,check all connections /grounds too  

[Neil_jdmr]

A loose battery connector would be the first thing id check.  I had this years ago and although it looked fine i could turn the connector on the post. Changed the clamp and all was great again

[Mavrik]

Check your ignition switch tumbler and connections... not unknown for the ignition barrel to FUBAR.

Edited September 6, 2022 by Mavrik

[futureechos]

Low voltage can cause weirdness with sensors on other cars.. presume you have checked voltage on the battery, although ideally the amp output needs to be checked. Potentially faulty battery or connections as mentioned above seems most likely. 

 

hope that helps. 

[trialsstar3]

Sounds like grounding problems... 

[Aaron]

This is either an intermittent supply or ground issue.  Not sure I'd start with the ignition barrel as the car went completely dead.  A faulty ignition barrel wouldn't prevent central locking from working, for example.

 

There could be several causes here, but a loose/faulty battery terminal connector seems the most logical as so many systems are being affected.  Check your battery, battery terminals and connectors first.  Try borrowing a battery temporarily to rule out replacing a fine battery, or get it voltage and discharge tested.  If that's fine, make your way to the grounding points: http://www.planet-9.com/downloads.php?do=file&id=353

 

Be mindful of any corrosion on the grounding points (harness or chassis) and be prepared to clear any corrosion you may find.  Do not smear Vaseline or the likes on the battery terminals/connectors, grounding points, or similar.  A clean metal-to-metal connection should be your target.

 

Good luck!

[Dan Norton]

Sorry fir slow response guys, been taken back a bit with HRH passing.

 

Many many thanks for all the replies and thoughts, and many thanks to Aaron for sharing the wiring diagram on planet 9.

 

I've got the car booked Into an auto electricians now, and the battery has gone flat now (probably what was still running inside has caused it to go flat).

 

The battery is good by the way, I got it tested at the garage that fitted it just as the gremlins started. 

 

It goes in on Wednesday but I'll print this thread out to assist them. 

 

I'll report back with what they find. 

[Dan Norton]

Good news everyone.

 

So the battery terminal had some corrosion on it, as did a ground point, both got cleaned up.

The positive terminal lead to the battery clamp was also a little lose, and i never actually realized it has a battery isolator valve on on the positive terminal.

This allows you to shut the power off from the battery to vehicle if you are leaving it stood for any length of time - quite a neat little modification actually (also slightly embarrassed i never knew what it was in almost 4 years of ownership).

 

The auto electrician gave it a full code diagnostic check for all the systems, battery drain, it has a draw of about 300MilliAmps after its shut its systems down (not enough for week to week driving to cause the battery to go flat, but advised if i'm not planning on using it, to use the isolator switch).

 

Clean bill of health given electronically, and cleaned off some corrosion.

 

£120 for half a days work of diagnostics and checks, including test drive- which i didn't think was bad to be fair.

 

Thanks for your help everyone.

[Neil_jdmr]

Great news Dan and glad you got it sorted.  Btw i leave mine for many weeks at a time due to the travel of my work but always just leave it on the ctek, handbrake off and in gear.

 

I have done this for many many years with my previous car that had a tiny Odyssey 680 battery and a temperamental rotary engine and it was always fine. 

 

My issue with battery isolators is the electronics will possibly forget certain settings like window limits,  pcm stuff etc.  Also imagine your wife thought she would do you a favour and close the bonnet, that would be a pita without a spare battery.

 

Anyway im rambling, glad you got it sorted.